Yes it works great on a PC - assuming something reasonably modern (In practical terms, I’d say any Windows 10 or Linux circa 2016+ environment.)
Django itself isn’t an “executable application” - it’s a Python library. If you’re able to run an appropriate Python implementation, Django isn’t going to cause you any problems.
I wouldn’t describe that as being an accurate representation.
The Django ORM Is an interface layer between Django and the database. You’re creating Models as a memory-based representation of the data in your database. You use the ORM instead of SQL to write queries (and updates). Creating HTML forms is a different part of Django, not directly related to the ORM.
The end goal is that you will create views - functions that receive http requests and generate responses. You will assign those views to urls.
The views can pull data from the database (using models), and then generate html data (and forms) to be returned to the browser.
I would strongly suggest you work your way through the official tutorial. Start with the Quick Install guide, and then jump into the tutorial.
Actually getting your hands on this is going to me a lot more effective than any number of words that I can write here.